The high quality SHM-CD (Super High Material CD) format features enhanced audio quality through the use of a special polycarbonate plastic. Using a process developed by JVC and Universal Music Japan discovered through the joint companies' research into LCD display manufacturing, SHM-CDs feature improved transparency on the data side of the disc, allowing for more accurate reading of CD data by the CD player laser head. SHM-CD format CDs are fully compatible with standard CD players.

This would only be worth it if the albums have been digitally remastered, otherwise it will just sound the same.
This is because the limitations stem from the masters not from the cd itself when looking at old albums. It may improve new albums but dont think it would improve old?!
[Edited 5/19/09 4:58am][Edited 5/19/09 4:59am]